substrate: rock siliceous, siliciferous, acidic | rock, stones, pebbles unspecified.
Thompson, J., 1997. American Arctic Lichens: The Microlichens.
Thallus large, to 13 cm across, of tiny flat areolae 0.1-1.0 mm broad, very dark sooty brown, bordered by a black hypothallus and a pale gray margin about 3 areolae (1 mm) wide, areolae very angular, mutually pressed together, with deep chinks between, thallus thin at edges to 1 mm thick centrally. Apothecia sunken in areolae, 1 per areola, sometimes with multiple disks; disk black, concave, dull, epruinose, a thin exciple sometimes visible; exciple dark brown, paraplectenchymatous, full of inspersed crystals, joining hypothecium, which is also dark brown; epihymenium brown; hymenium pale below, brown above, 65-75 μm paraphyses coherent, not branched, not moniliform, septate, 3 μm with tips to 6 μm and brown; asci clavate; spores 8, biseriate, hyaline, often with gelatinous halo, 12-12.5 X 6.5-7.5 μm.
Reactions: K—, C—, P—, 1+ blue, known thus far only from the type locality on the Pit-megea River, on the north slope of Alaska. The type locality may have been extirpated during oil pipeline development.